Odds of Late Season Tropical Threat Growing

Next named storm could become a powerful hurricane in the Caribbean as soon as this weekend, but its ultimate course remains unclear

A significant late-season tropical system is poised to come together later this week and could strengthen into a formidable November hurricane by this weekend or early next week as it meanders in the western Caribbean.

Interests from Jamaica and Haiti in the east to Nicaragua, Honduras, Belize, and the Yucatán Peninsula in the west will need to monitor the growing threat, especially by late week into the weekend.

Unfortunately competing steering currents may leave a powerful hurricane adrift into the first part of next week, when it could bend northward toward the Gulf of Mexico or Florida.

While it’s too early to know what path the future storm may take, with credible scenarios paving a path into the Gulf and unusually conducive conditions ahead for November, Floridians will want to pay extra attention to the forecasts in the days ahead.

The next name on the list is Sara.

Thursday-Friday development

The two features we’re tracking today are a tropical wave plodding west through the Windward Passage between Haiti and Cuba today and a strip of storminess and spin (the monsoon trough) stretching from the eastern Pacific into the southwestern Caribbean.

These two features are expected to come together in the western Caribbean off the coasts of Honduras and Nicaragua by Thursday and Friday, which is when development should happen in earnest.

The weekend tug-of-war

As we discussed in yesterday’s newsletter, the first potential exit ramp for the organizing system will come late Friday into Saturday as a cold front dives southward through Florida and into the Caribbean.

Although the approaching front will be strong enough to tug the system briefly east, models suggest it won’t fully latch on to the system to whisk it eastward and out to sea.

If it’s left behind as anticipated, high pressure will build in quickly in the wake of the front to turn what’s likely to be a strengthening hurricane back westward toward Central America and perhaps bending it northward toward the Gulf of Mexico or Florida for early next week.

What happens into next week?

Assuming the developing storm misses its first exit ramp east this weekend, we’ll need to see how far west it’s driven by high pressure to start next week.

One possible scenario is it moves fully inland over Central America or southern Mexico’s Yucatán Peninsula which could disrupt its circulation before reaching the Gulf of Mexico.

Another possibility is it remains offshore and turns into the Gulf or toward Florida for the middle part of next week.

Forecast low-pressure tracks from the overnight run of the European model ensemble system. Each line represents a possible track scenario based on different starting positions. The chaotic nature of the tracks – appropriately known as a “squashed spider” – suggests high uncertainty in the forecast, from a system escaping eastward into the Atlantic to a system drifting inland over Central America this weekend to a storm sneaking into the Gulf of Mexico or toward Florida for next week. Interests in the western Caribbean and Florida should continue to monitor the forecasts. Credit: Weathernerds.org

It’s worth stressing the high uncertainty in the forecast into early next week. Weather patterns in late fall can be much more volatile than in the dog days of summer, and until a system forms, small differences in where the center forms can have outsized implications on where it ends up a week from today.

The bottom line: don’t take any forecast for next week as the final word. Expect swings – maybe big swings – in the forecast. But as we mentioned yesterday, the upper-level winds will be unusually conducive for the third week of November and with credible scenarios toward Florida and the Gulf, we’ll need to stay patient and stay vigilant.